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The lacrimal drainage system is the pathway that carries tears away from the eye surface and into the nose. It begins at the lacrimal puncta on the eyelids, continues through the canaliculi and lacrimal sac, and ends at the nasolacrimal duct. This system helps prevent tears from overflowing and supports a stable tear film. Blockage anywhere along the pathway can cause watery eyes and increase infection risk.
read more about lacrimal drainage system ...Tears collect at the inner corner of the eye and enter the upper and lower puncta. They pass through the canaliculi, often joining at a common canaliculus before entering the lacrimal sac. From the lacrimal sac, tears travel down the nasolacrimal duct and open into the inferior meatus of the nasal cavity. The connection to the nose is why crying can cause nasal drainage.
Blinking helps move tears through the drainage system by changing pressure around the canaliculi and lacrimal sac. Valves within the system help promote one way movement and reduce backflow toward the puncta. If the eyelid pump is weak, tearing can occur even when the ducts are open. Facial nerve weakness is one example that can reduce pump function.
Drainage issues can be structural or functional.
Symptoms often include epiphora, mucus discharge, and crusting.
Evaluation may include slit-lamp exam, dye disappearance testing, and irrigation or probing to locate the obstruction. Imaging may be used when anatomy is unclear or a mass is suspected. Treatment can include punctal dilation, stenting, balloon procedures, or dacryocystorhinostomy, which creates a new drainage pathway when the nasolacrimal duct is blocked. Treating eyelid position and surface inflammation is also important for lasting relief.
Tears that drain through the nasolacrimal duct empty into the nasal cavity. When tear production increases, more fluid enters the nose, leading to a runny nose.
Dacryocystitis is an infection of the lacrimal sac, often related to drainage obstruction. It can cause pain, redness, swelling near the inner corner, and discharge. It needs prompt medical evaluation to prevent complications.
Common tests include observing tear pooling, dye disappearance testing, and gentle irrigation of the drainage system. These help determine whether blockage is present and where it is located.
Yes. If the puncta are not positioned against the tear lake due to eyelid laxity or ectropion, tears may not enter the system properly. Weak blink pump function can also contribute to watery eyes.
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